/** @file
  MiniVisor Advanced Anti-Detection Library
  
  This file implements enterprise-grade anti-detection capabilities including
  advanced hypervisor concealment, timing attack protection, and behavioral
  pattern masking.
  
  Copyright (c) 2024, MiniVisor Project. All rights reserved.
  SPDX-License-Identifier: BSD-2-Clause-Patent
**/

#include <Uefi.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/TimerLib.h>
#include <Library/IoLib.h>
#include <Library/UefiBootServicesTableLib.h>

#include "../Include/MiniVisorAntiDetection.h"

//
// Global anti-detection context
//
STATIC ANTI_DETECTION_CONTEXT gAntiDetectionContext = {0};
STATIC BOOLEAN gAntiDetectionInitialized = FALSE;

//
// Advanced timing protection
//
STATIC UINT64 gLastTimingCheck = 0;
STATIC UINT64 gTimingJitterSeed = 0;
STATIC UINT32 gTimingPattern[16] = {0};

//
// Behavioral pattern masking
//
STATIC UINT32 gBehavioralState = 0;
STATIC UINT64 gLastBehavioralUpdate = 0;
STATIC UINT32 gBehavioralPatterns[8] = {0};

//
// Memory layout obfuscation
//
STATIC UINT64 gMemoryLayoutSeed = 0;
STATIC UINT32 gMemoryPatterns[32] = {0};

/**
  Initialize advanced anti-detection system.
  
  @param[in] Level         Anti-detection level.
  
  @retval EFI_SUCCESS      Initialization successful.
  @retval Others           Initialization failed.
**/
EFI_STATUS
EFIAPI
InitializeAntiDetection (
  IN UINTN Level
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  
  if (gAntiDetectionInitialized) {
    return EFI_ALREADY_STARTED;
  }
  
  DEBUG((DEBUG_INFO, "[Anti-Detection] Initializing advanced anti-detection system\n"));
  
  // Initialize context
  ZeroMem(&gAntiDetectionContext, sizeof(ANTI_DETECTION_CONTEXT));
  gAntiDetectionContext.Level = Level;
  gAntiDetectionContext.Initialized = TRUE;
  
  // Initialize timing protection
  gLastTimingCheck = CurrentTsc;
  gTimingJitterSeed = CurrentTsc ^ (CurrentTsc >> 32);
  
  // Generate timing patterns
  for (UINT32 i = 0; i < 16; i++) {
    gTimingPattern[i] = (UINT32)(gTimingJitterSeed ^ (i * 0x12345678ULL));
  }
  
  // Initialize behavioral masking
  gBehavioralState = (UINT32)CurrentTsc;
  gLastBehavioralUpdate = CurrentTsc;
  
  for (UINT32 i = 0; i < 8; i++) {
    gBehavioralPatterns[i] = (UINT32)(CurrentTsc ^ (i * 0x87654321ULL));
  }
  
  // Initialize memory layout obfuscation
  gMemoryLayoutSeed = CurrentTsc ^ 0xDEADBEEF;
  
  for (UINT32 i = 0; i < 32; i++) {
    gMemoryPatterns[i] = (UINT32)(gMemoryLayoutSeed ^ (i * 0xABCDEF00ULL));
  }
  
  gAntiDetectionInitialized = TRUE;
  
  DEBUG((DEBUG_INFO, "[Anti-Detection] Advanced anti-detection system initialized\n"));
  
  return EFI_SUCCESS;
}

/**
  Apply advanced timing protection.
  
  @param[in] Context       Anti-detection context.
  
  @retval EFI_SUCCESS      Timing protection applied.
**/
EFI_STATUS
EFIAPI
ApplyTimingProtection (
  IN ANTI_DETECTION_CONTEXT *Context
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  UINT32 JitterIndex = (UINT32)(CurrentTsc & 0xF);
  UINT32 JitterValue = gTimingPattern[JitterIndex];
  
  if (!gAntiDetectionInitialized) {
    return EFI_NOT_READY;
  }
  
  // Apply timing jitter
  if ((CurrentTsc - gLastTimingCheck) > 1000) {
    // Add random delays to prevent timing analysis
    for (UINT32 i = 0; i < (JitterValue & 0xFF); i++) {
      AsmCpuid(0, NULL, NULL, NULL, NULL);
    }
    
    gLastTimingCheck = CurrentTsc;
  }
  
  // Update timing patterns
  gTimingPattern[JitterIndex] = (gTimingPattern[JitterIndex] * 0x41C6CE57) ^ CurrentTsc;
  
  return EFI_SUCCESS;
}

/**
  Apply behavioral pattern masking.
  
  @param[in] Context       Anti-detection context.
  
  @retval EFI_SUCCESS      Behavioral masking applied.
**/
EFI_STATUS
EFIAPI
ApplyBehavioralMasking (
  IN ANTI_DETECTION_CONTEXT *Context
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  UINT32 PatternIndex = (UINT32)(CurrentTsc & 0x7);
  
  if (!gAntiDetectionInitialized) {
    return EFI_NOT_READY;
  }
  
  // Update behavioral state
  if ((CurrentTsc - gLastBehavioralUpdate) > 10000) {
    gBehavioralState = (gBehavioralState * 0x19660D) ^ (UINT32)CurrentTsc;
    gLastBehavioralUpdate = CurrentTsc;
  }
  
  // Apply behavioral patterns
  gBehavioralPatterns[PatternIndex] = (gBehavioralPatterns[PatternIndex] * 0x8088405) ^ gBehavioralState;
  
  return EFI_SUCCESS;
}

/**
  Apply memory layout obfuscation.
  
  @param[in] Context       Anti-detection context.
  
  @retval EFI_SUCCESS      Memory obfuscation applied.
**/
EFI_STATUS
EFIAPI
ApplyMemoryObfuscation (
  IN ANTI_DETECTION_CONTEXT *Context
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  UINT32 MemoryIndex = (UINT32)(CurrentTsc & 0x1F);
  
  if (!gAntiDetectionInitialized) {
    return EFI_NOT_READY;
  }
  
  // Update memory patterns
  gMemoryPatterns[MemoryIndex] = (gMemoryPatterns[MemoryIndex] * 0x19660D) ^ (UINT32)CurrentTsc;
  
  return EFI_SUCCESS;
}

/**
  Advanced CPUID spoofing with multi-strategy approach.
  
  @param[in] Function      CPUID function.
  @param[in] SubFunction   CPUID sub-function.
  @param[in,out] Eax       EAX register.
  @param[in,out] Ebx       EBX register.
  @param[in,out] Ecx       ECX register.
  @param[in,out] Edx       EDX register.
  
  @retval EFI_SUCCESS      CPUID spoofing applied.
**/
EFI_STATUS
EFIAPI
AdvancedCpuidSpoofing (
  IN UINT32 Function,
  IN UINT32 SubFunction,
  IN OUT UINT32 *Eax,
  IN OUT UINT32 *Ebx,
  IN OUT UINT32 *Ecx,
  IN OUT UINT32 *Edx
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  UINT32 Strategy = (UINT32)(CurrentTsc & 0x3);
  
  if (!gAntiDetectionInitialized) {
    return EFI_NOT_READY;
  }
  
  // Apply timing protection
  ApplyTimingProtection(&gAntiDetectionContext);
  
  // Apply behavioral masking
  ApplyBehavioralMasking(&gAntiDetectionContext);
  
  // Multi-strategy CPUID spoofing
  switch (Strategy) {
    case 0: // Hide virtualization completely
      if (Function == 1) {
        *Ecx &= ~(BIT5 | BIT31); // Hide VMX and hypervisor
      }
      break;
      
    case 1: // Fake VMware signature
      if (Function >= 0x40000000 && Function <= 0x40000010) {
        *Eax = 0x40000010;
        *Ebx = 0x61774D56; // "VMwa"
        *Ecx = 0x4D566572; // "reVM"
        *Edx = 0x65726177; // "ware"
      }
      break;
      
    case 2: // Fake Hyper-V signature
      if (Function >= 0x40000000 && Function <= 0x40000010) {
        *Eax = 0x40000005;
        *Ebx = 0x7263694D; // "Micr"
        *Ecx = 0x666F736F; // "osof"
        *Edx = 0x76482074; // "t Hv"
      }
      break;
      
    case 3: // Dynamic randomization
      if (Function >= 0x40000000 && Function <= 0x40000010) {
        *Eax = 0x40000000 + (CurrentTsc & 0xF);
        *Ebx = (UINT32)(CurrentTsc ^ 0x12345678);
        *Ecx = (UINT32)((CurrentTsc >> 32) ^ 0x87654321);
        *Edx = (UINT32)(CurrentTsc ^ 0xDEADBEEF);
      }
      break;
  }
  
  return EFI_SUCCESS;
}

/**
  Advanced MSR spoofing with comprehensive coverage.
  
  @param[in] MsrNumber     MSR number.
  @param[in] IsWrite       TRUE for write operation.
  @param[in,out] MsrValue  MSR value.
  
  @retval EFI_SUCCESS      MSR spoofing applied.
**/
EFI_STATUS
EFIAPI
AdvancedMsrSpoofing (
  IN UINT32 MsrNumber,
  IN BOOLEAN IsWrite,
  IN OUT UINT64 *MsrValue
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  UINT32 Strategy = (UINT32)(CurrentTsc & 0x7);
  
  if (!gAntiDetectionInitialized) {
    return EFI_NOT_READY;
  }
  
  // Apply timing protection
  ApplyTimingProtection(&gAntiDetectionContext);
  
  // Apply memory obfuscation
  ApplyMemoryObfuscation(&gAntiDetectionContext);
  
  // Comprehensive MSR spoofing
  switch (MsrNumber) {
    case 0x480: // IA32_VMX_BASIC
    case 0x481: // IA32_VMX_PINBASED_CTLS
    case 0x482: // IA32_VMX_PROCBASED_CTLS
    case 0x483: // IA32_VMX_EXIT_CTLS
    case 0x484: // IA32_VMX_ENTRY_CTLS
    case 0x485: // IA32_VMX_MISC
    case 0x486: // IA32_VMX_CR0_FIXED0
    case 0x487: // IA32_VMX_CR0_FIXED1
    case 0x488: // IA32_VMX_CR4_FIXED0
    case 0x489: // IA32_VMX_CR4_FIXED1
    case 0x48A: // IA32_VMX_VMCS_ENUM
    case 0x48B: // IA32_VMX_PROCBASED_CTLS2
    case 0x48C: // IA32_VMX_EPT_VPID_CAP
    case 0x48D: // IA32_VMX_TRUE_PINBASED_CTLS
    case 0x48E: // IA32_VMX_TRUE_PROCBASED_CTLS
    case 0x48F: // IA32_VMX_TRUE_EXIT_CTLS
    case 0x490: // IA32_VMX_TRUE_ENTRY_CTLS
    case 0x491: // IA32_VMX_VMFUNC
      // Hide Intel VMX MSRs completely
      if (!IsWrite) {
        *MsrValue = 0;
      }
      break;
      
    case 0xC0010010: // SYS_CFG
    case 0xC0010015: // HWCR
    case 0xC0010058: // MMIO Configuration Base
    case 0xC0010059: // MMIO Configuration Limit
      // Hide AMD virtualization MSRs
      if (!IsWrite) {
        *MsrValue &= ~0xFF00000000000000ULL; // Clear virtualization bits
        *MsrValue ^= ((UINT64)Strategy << 16) & 0x00FF000000000000ULL;
      }
      break;
      
    default:
      // Apply general randomization for other MSRs
      if (!IsWrite && (MsrNumber >= 0x40000000 || MsrNumber >= 0xC0000000)) {
        *MsrValue ^= (UINT64)Strategy << 32;
      }
      break;
  }
  
  return EFI_SUCCESS;
}

/**
  Advanced RDTSC/RDTSCP spoofing with timing attack protection.
  
  @param[in,out] TscValue  TSC value.
  @param[in,out] AuxValue  Auxiliary value (for RDTSCP).
  
  @retval EFI_SUCCESS      TSC spoofing applied.
**/
EFI_STATUS
EFIAPI
AdvancedTscSpoofing (
  IN OUT UINT64 *TscValue,
  IN OUT UINT32 *AuxValue OPTIONAL
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  UINT32 Strategy = (UINT32)(CurrentTsc & 0xF);
  
  if (!gAntiDetectionInitialized) {
    return EFI_NOT_READY;
  }
  
  // Apply timing protection
  ApplyTimingProtection(&gAntiDetectionContext);
  
  // Apply behavioral masking
  ApplyBehavioralMasking(&gAntiDetectionContext);
  
  // Advanced TSC spoofing
  switch (Strategy) {
    case 0: // Add small random jitter
      *TscValue += (CurrentTsc & 0xFFF);
      break;
      
    case 1: // Add larger random offset
      *TscValue += (CurrentTsc & 0xFFFF);
      break;
      
    case 2: // Use fake TSC value
      *TscValue = CurrentTsc ^ 0x123456789ABCDEFULL;
      break;
      
    case 3: // Add time-based offset
      *TscValue += (CurrentTsc >> 8) & 0xFFFF;
      break;
      
    default: // Complex randomization
      *TscValue = (*TscValue * 0x19660D) ^ CurrentTsc;
      break;
  }
  
  // Spoof auxiliary value for RDTSCP
  if (AuxValue != NULL) {
    switch (Strategy & 0x3) {
      case 0:
        *AuxValue = (UINT32)(CurrentTsc & 0xFFFF);
        break;
      case 1:
        *AuxValue = (UINT32)((CurrentTsc >> 16) & 0xFFFF);
        break;
      case 2:
        *AuxValue = (UINT32)(CurrentTsc ^ 0xDEADBEEF);
        break;
      case 3:
        *AuxValue = (UINT32)((*AuxValue * 0x41C6CE57) ^ CurrentTsc);
        break;
    }
  }
  
  return EFI_SUCCESS;
}

/**
  Detect and respond to analysis attempts.
  
  @param[in] Context       Anti-detection context.
  
  @retval BOOLEAN          TRUE if analysis detected.
**/
BOOLEAN
EFIAPI
DetectAnalysisAttempt (
  IN ANTI_DETECTION_CONTEXT *Context
  )
{
  UINT64 CurrentTsc = AsmReadTsc();
  UINT64 TimeDiff = CurrentTsc - gLastTimingCheck;
  
  if (!gAntiDetectionInitialized) {
    return FALSE;
  }
  
  // Detect timing-based analysis
  if (TimeDiff < 100) {
    // Too fast - possible automated analysis
    DEBUG((DEBUG_WARN, "[Anti-Detection] Timing-based analysis detected\n"));
    return TRUE;
  }
  
  if (TimeDiff > 0x100000000ULL) {
    // Too slow - possible manual analysis
    DEBUG((DEBUG_WARN, "[Anti-Detection] Manual analysis detected\n"));
    return TRUE;
  }
  
  // Detect pattern-based analysis
  UINT32 PatternIndex = (UINT32)(CurrentTsc & 0x7);
  if (gBehavioralPatterns[PatternIndex] == 0) {
    // Suspicious pattern - possible analysis
    DEBUG((DEBUG_WARN, "[Anti-Detection] Pattern-based analysis detected\n"));
    return TRUE;
  }
  
  return FALSE;
}

/**
  Apply comprehensive anti-detection measures.
  
  @param[in] Context       Anti-detection context.
  
  @retval EFI_SUCCESS      Anti-detection measures applied.
**/
EFI_STATUS
EFIAPI
ApplyComprehensiveAntiDetection (
  IN ANTI_DETECTION_CONTEXT *Context
  )
{
  if (!gAntiDetectionInitialized) {
    return EFI_NOT_READY;
  }
  
  // Apply all anti-detection measures
  ApplyTimingProtection(Context);
  ApplyBehavioralMasking(Context);
  ApplyMemoryObfuscation(Context);
  
  // Check for analysis attempts
  if (DetectAnalysisAttempt(Context)) {
    // Apply additional countermeasures
    DEBUG((DEBUG_WARN, "[Anti-Detection] Applying countermeasures\n"));
    
    // Add extra delays
    for (UINT32 i = 0; i < 1000; i++) {
      AsmCpuid(0, NULL, NULL, NULL, NULL);
    }
    
    // Update patterns more aggressively
    UINT64 CurrentTsc = AsmReadTsc();
    for (UINT32 i = 0; i < 16; i++) {
      gTimingPattern[i] = (UINT32)(CurrentTsc ^ (i * 0x12345678ULL));
    }
    
    for (UINT32 i = 0; i < 8; i++) {
      gBehavioralPatterns[i] = (UINT32)(CurrentTsc ^ (i * 0x87654321ULL));
    }
  }
  
  return EFI_SUCCESS;
}

/**
  Get anti-detection statistics.
  
  @param[out] Stats        Anti-detection statistics.
  
  @retval EFI_SUCCESS      Statistics retrieved.
**/
EFI_STATUS
EFIAPI
GetAntiDetectionStats (
  OUT ANTI_DETECTION_STATS *Stats
  )
{
  if (!gAntiDetectionInitialized || Stats == NULL) {
    return EFI_INVALID_PARAMETER;
  }
  
  Stats->TimingProtectionCount = gAntiDetectionContext.TimingProtectionCount;
  Stats->BehavioralMaskingCount = gAntiDetectionContext.BehavioralMaskingCount;
  Stats->MemoryObfuscationCount = gAntiDetectionContext.MemoryObfuscationCount;
  Stats->AnalysisAttemptsDetected = gAntiDetectionContext.AnalysisAttemptsDetected;
  Stats->CountermeasuresApplied = gAntiDetectionContext.CountermeasuresApplied;
  
  return EFI_SUCCESS;
}

//
// Library class constructor
//
EFI_STATUS
EFIAPI
MiniVisorAntiDetectionLibConstructor (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  return EFI_SUCCESS;
}
